DESCRIPTION:(provided by applicant) The role of the basal ganglia in movement related disorders, such as Parkinson's disease, has been well documented. The overall movement deficits of these patients are partly due to difficulties in the sequencing of motor actions, and these deficits can be construed as separate from their elemental motor difficulties. As symptoms of Parkinson's patients include deficits on over-learned movement sequences, the mechanisms underlying these normally "automated" behaviors may be more closely related to innate stereotypical sequences, than to the arbitrary learned sequences typically used in animal models of sequencing. Indeed, experimental results confirm this notion. While similarities between the representation of well-learned and innate sequences are considerable, they are not complete. The goal of the present proposal is to understand the neural mechanisms underlying both types of sequential motor control by recording from ensembles of striatal neurons in rats while they perform natural or learned motor sequences. Neural activity, anatomical area, and neuronal interactions will be compared and contrasted across these two motor sequences. The ability of dopaminergic drugs to alter both types of sequential behavior and the related neuronal activity will also be evaluated, in order to further develop treatment strategies for Parkinson's disease.